Data is a collection of facts such as values or measurements.
Data can be in the form of numbers, words, measurements, observations or even descriptions of some things.
Types Of Data:
Data can be of two types- Qualitative and Quantitative
Qualitative data provides a descriptive information about something.
Quantitative data provides numerical information about something.
Quantitative data is of two types- Discrete and Continuous
Discrete data can only take certain values like whole numbers
Continuous data can take any value within a range
Note: Discrete data is countable while continuous data is measurable.
Simple example is given below to have a better understanding of the types of data:
- It is tawny brown in colour and is covered with dark black spots
- It has two black stripes which look like tear-tracks
- It is the fastest animal in the world
- It has four legs
- It has two kids
- The average weight of cheetah is 50 to 60 kg
- The height of cheetah is 70-90 cm.
Collection of data:
Data can be collected in many ways. The simplest method is to observe directly.
In case if you want to find the number of cycles passing certain point on a road in 20 minutes interval of time.
You can stand at that particular point and count the number of cycles that pass by in that interval.
Census Or Sample:
Census is collecting data for every member of the group ( whole population)
Sample is collecting data for selected member of the group.
There are 40 students in a classroom. you can ask everyone ( all 40) what their height is. That is census. or you could just ask some 10 students what their height is. That is Sample.
Census is accurate but hard to calculate.
Sample is not as accurate as census but may be good enough and easy to calculate